#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
int main()
{
	int n;
	double sum;
	scanf("%d",&n);
	for(int i = 0;i<n;i++)
	{
		double x;
		scanf("%lf",&x);
		sum += x;
	}
	printf("%.12lf\n",sum/(1.0*n));
}
